WEBVTT
00:00:00.660 --> 00:00:20.300
Determine the upper and lower quartiles of the following set of data: 114, 103, 50, 52, 95, 103, 93, 53, 65, 57, 52, 89, 111, 89, and 96.
00:00:21.060 --> 00:00:25.800
We first need to put these number in ascending order from smallest to largest.
00:00:26.630 --> 00:00:43.430
Our smallest number is 50, then 52, then another 52, 53, 57, 65, 89, 89, 93, 95, 96, 103, 103, 111.
00:00:43.920 --> 00:00:46.570
And then lastly our largest number is 114.
00:00:47.160 --> 00:00:48.670
Here we have 15 numbers.
00:00:49.030 --> 00:00:51.440
And the median will be the middle number.
00:00:52.420 --> 00:00:54.850
And the middle number of 15 would be eight.
00:00:54.960 --> 00:00:57.160
There are seven numbers on each side.
00:00:57.940 --> 00:01:04.290
Now to find the upper and lower quartiles, we need to find the middle of the lower half and the middle of the upper half.
00:01:04.780 --> 00:01:07.060
So here we have our lower half and our upper half.
00:01:07.540 --> 00:01:13.080
The middle number of seven, the fourth number, would be the lower quartile.
00:01:13.420 --> 00:01:15.680
Itâ€™s the middle of the seven numbers.
00:01:15.970 --> 00:01:17.980
So 53 is our lower quartile.
00:01:18.630 --> 00:01:21.600
And then the 12th number will be the upper quartile.
00:01:21.910 --> 00:01:24.050
So 103 is the upper quartile.
00:01:24.390 --> 00:01:30.500
So once again, our final answer will be that the lower quartile is 53 and the upper quartile is 103.